Rounding Whole numbers

Posted on 2011-09-21
Last Modified: 2012-05-12
I'm having a hard time rounding. I pull a quantity from a stored procedure and need to round this number up. It will be used as the MaximumScale number for a Excel chart. I never know legth (number of digits it will be) examples:

2300 needs to be 2500
2500 needs to be 3000
234000 needs to be 250000 and so forth.
Been trying to use Math.Ceiling and Math.Floor.

Math.Ceiling(Qty / Num) * num
But not sure how to determine num or is there a better way.
Question by:MadIce
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 7
  • 5

Expert Comment

ID: 36576799

Math.Round(Qty / num) * num could work for you, where num is the "rounder".


double qty = 2300;
double num = 500;
double result = Math.Round(qty / num) * num;

that would give you 2500.

I hope it is useful.

Best Regards,

Author Comment

ID: 36576828
That would probably work if I can determine what num should be. num could be 5, 50, 500, 5000, 50000 and so forth. How can I determine that number?
LVL 37

Expert Comment

by:Neil Russell
ID: 36576847
That dont help with the 3rd example.

num needs to be 5 * 10^( the length of qty in digits -2)

I think?

MS Dynamics Made Instantly Simpler

Make Your Microsoft Dynamics Investment Count  & Drastically Decrease Training Time by Providing Intuitive Step-By-Step WalkThru Tutorials.

LVL 37

Expert Comment

by:Neil Russell
ID: 36576979
Very quickly in excel so you can visualise.....

 Formula in excel
LVL 37

Expert Comment

by:Neil Russell
ID: 36577041

Dim Qty as Double = 243000D
Dim StrQty as String = Qty.ToString("D")
Dim LenFactor as Integer = StrQty.Length() - 2

Dim Answer = math.ceiling(Qty+1,5*10^LenFactor)

Think that works but not on a machine with .net on right now.

Open in new window


Author Comment

ID: 36577113

I get an error for math.ceiling. doesn't except this many arguments

Author Comment

ID: 36577222
OK, got part of it.

Dim Qty as int32 = spReturnNum   'Say it = 27105
dim num as int32 = (Math.Log10(Qty)) - 1
dim qt as int32 = Math.Ceiling(Qty) + (5 * 10 ^ num)

This gives me 32105 but what I really need is 32000.
The (5 * 10 ^ num) part has helped.
LVL 37

Accepted Solution

Neil Russell earned 500 total points
ID: 36577262
Ok so .net ceiling is different, ny bad....

Dim Answer = math.Round((Qty+1)/(5*10^LenFactor)) * (5*10^LenFactor)


Author Comment

ID: 36577381
That's very close but can round down. I never want to round down.
LVL 37

Expert Comment

by:Neil Russell
ID: 36577520
Dim Answer = math.Round((Qty+ (5*10^LenFactor) -1 ) / (5*10^LenFactor)) * (5*10^LenFactor)

LVL 37

Expert Comment

by:Neil Russell
ID: 36577524
Hmmm no, Grrrrrr
Bloody .NET!
LVL 37

Expert Comment

by:Neil Russell
ID: 36577575
Or will it..... lol

Its 01:00 here and my eyes have gone! Good luck, bed time.

Author Closing Comment

ID: 36581513
I believe what I have below is working. The (5 * 10 ^ num) part really helped
Thanks alot.

Dim Qty As Int32 = SPGetQty
Dim Num as Int32 = (Math.Log10(Qty)) - 1
Dim answer As Int32 = (Math.Round((Qty) / (5 * 10 ^ num)) * (5 * 10 ^ num))

If Qty >= answer Then
    answer += 5 * 10 ^ num
End If

Featured Post

Creating Instructional Tutorials  

For Any Use & On Any Platform

Contextual Guidance at the moment of need helps your employees/users adopt software o& achieve even the most complex tasks instantly. Boost knowledge retention, software adoption & employee engagement with easy solution.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

It’s quite interesting for me as I worked with Excel using for some time. Here are some topics which I know want to share with others whom this might help. First of all if you are working with Excel then you need to Download the Following …
Calculating holidays and working days is a function that is often needed yet it is not one found within the Framework. This article presents one approach to building a working-day calculator for use in .NET.
Michael from AdRem Software explains how to view the most utilized and worst performing nodes in your network, by accessing the Top Charts view in NetCrunch network monitor ( Top Charts is a view in which you can set seve…
This is my first video review of Microsoft Bookings, I will be doing a part two with a bit more information, but wanted to get this out to you folks.
Suggested Courses

623 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question